UHPC North America UHPC North America · Repair and retrofit of bridges using UHPC Gaston Doiron,...

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2016 ICRI Kick‐Off Party | February 1, 2016

Repair and retrofit of bridges using UHPCGaston Doiron, P.Eng., M.Eng.Project Manager, LafargeHolcim


UHPC in North America

UHPC has been used on bridges projects for over 10 years in NA. Precast deckpanels connected with field cast UHPC joints has been the most popularapplication. Approximately 200 projects completed in more than 25 states andprovinces to date.UHPC has also been used for:

– Structural overlays– Headers and link slabs to replace traditional expansion joints– Jackets for columns/piers– Pier cap to column connections– UHPC precast elements to widen and strengthen existing bridges


UHPC projects in North America


UHPC projects in North America

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UHPC matrix

30 MPa (4 ksi) normal

150 MPa (22 ksi) UHPC

70 MPa (10 ksi) high performance


UHPC vs Normal Concrete

CharacteristicsNormal

Concrete Ratio UHPC

Mechanical

Compression - MPa (psi) 20 – 40 (3,000 - 6,000) 6 x 140 – 160 (20,000 – 23,000)

Flexure – MPa (psi) 30 (4,000)

Elastic Tensile Strength – MPa (psi) 8 (1,200)

Water / Cement ratio 0.40 - 0.70 < 2 < 0.25

Durability

Chloride ions diffusion(coulombs) > 2000 20 x < 100

Freeze / thaw cyclesscalling (g/m2) > 1000 100 x < 10

Abrasion (kg/m2) 1 100 x 0.01


Steel fibers

Fibers = Ductility


UHPC in Flexure

Fibers = Stain hardening (1st crack at 4,000 psi)

0

510

1520

25

3035

4045

50

0.0 0.5 1.0 1.5 2.0Deflection (mm)

Equivalent Stress (M

Pa) Ductal

HPC 80

UHPC

HPC

First Crack

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Chlorides penetration test

US Army Corps test site in Maine

UHPC steamed cured

UHPC ambient temp. cured

UHPC


Design Guides ‐ FHWA

FHWA has published over 40 reports, TechNotes and Guidelines


Design Standard – SIA 2052 ‐ 2016

Swiss Society of Engineers and Architects


Design Standard ‐ NF P 18‐470 ‐ 2016

AFNOR (Association française de normalisation)

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• In December of 2015, the Canadian Standards Association (CSA) formed a new “Working Group on UHPC” under A23.1, Chapter 8, with the mandate to develop a new annex on UHPC materials (CSA A23.1, 2014). Target 2019 edition of the next CSA A23.1‐19.

• American Concrete Institute (ACI)239 ‐ Ultra‐High Performance Concrete239‐A Emerging Technology Report239‐B Report on UHPC239‐C Structural Design on UHPC239‐D Materials & Methods of Construction with UHPC

Design Guidelines US/CanadaCommittee work in progress


Batching equipment

On site batching is the preferred option for most projects.We have a fleet of portable mixers which can be rented by contractors.

A size for every job

4.5 m3 per truck(6 yd3)

0.15 m3 batches ‐ 0.6 m3 / hour(0.2 yd3) (0.8 yd3)

0.5 m3 batches ‐ 2 m3 / hour(0.65 yd3) (2.6 yd3)

1.0 m3 batches ‐ 4 m3 / hour(1.3 yd3) (5.2 yd3)


Applications


Joint fill / Closure Pours / Haunches

Typical connection detail

Installation of precast panels

UHPC has been used to joint precast elements together and also used to secure the deck to the supporting beams by filling the haunches and shear keys pockets.

DOT’s elaborate their own specificationsand designs.

Main issue: UHPC joints are now the stronger elements and not affected by live loads, freeze‐thaw or deicing salts.

Solution: UHPC joints allows for faster construction because no need to form decks on site and wait for deck curing. Also, ideal for remote areas where the contractor is not dependant on the availability of ready mix.

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Pulaski Skyway, NJ 2014/17

5.5 km (3.5 miles) ‐ 4 lanes


Pulaski Skyway, NJ

Traffic maintained on 2 lanes during construction


Nipigon Bridge, east of Thunder Bay

Grouting precast deck panels with UHPC


Surface before applying the overlay

Typical 200 mm (8 in) wide UHPC joints

UHPC casting completed

Bridge 56 precast panels – 3 span bridge ‐‐ 83 m (270 ft) x 17 m (56 ft)

Peoria Street Bridge, Chicago, IL

Photos by David Liu

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UHPC overlay

Application of dense layer of strain‐hardening UHPC with 25 to 60 mm(1 in to 2.5 in) thickness applied on the superstructure in zones of severe environmental and mechanical loads.

UHPC Reinforced UHPC

h ≥ 25 mmh ≥ 35 to 60 mm

reinforced concrete

protection protection +

strengthening

reinforced concrete


UUPC overlay formulationSelf leveling mix to thixotropic mix


UHPC overlay – large project

Batching 60 to 75 m3 (75 to 100 yd3) capacity per day

Motorized buggies to bring material in front of the paver Portable batching plant; one silo for sand, one silo for the premix, 2 high shear mixers 1 m3 (1.5 yd3 ) batches


UHPC overlay

Placing – industrialized system

1 spread in front of machine

23

vibration

finished surface

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Chillon Viaducts, Switzerland 2014‐15

Work staged over 2 years with traffic maintained on one of the structures

Concrete paver developped by WALO

45 mm (1.75 in) cast‐in‐place overlay with rebar reinforcementThixotropic mix used to cast on 7% slope

2 parallel structureseach 12 m (40 ft) wide 2 km (1.2 mile) long51,000 m2 (61,000 yd2) total deck areaOriginal segmental box system built 1969

Main issue: ASR (alkali silica reaction) and lost of concrete performance

Solution: Thin structural UHPC overlay provides waterproofing to halt ASR progression and increase substantially the strength of the deck

UHPC cheaper alternative


Concrete paver with customized dispensing system at the front

On site portable batching plant – 2 mixers

Material brought to the concrete machine with motorized buggies

Hydro demolition

Chillon Viaducts


Iowa DOT, Buchanan Country, 2016

Diamond grinding equipment used to provide grooved running surface

Placing using a simple vibrating screed machine

38 mm (1.5 in) cast‐in‐place overlayThixotropic mix used to cast on 5% slope

30 m (100 ft) long, 3‐span deck8.5 m (28 ft) wide260 m2 (310 yd2) total deck area

Main issue: Pilot project to evaluate the constructability and performance of a UHPC overlay

Solution: Current low lump concreteoverlays are not performing optimally. A more durable UHPC product would provide added durability. This pilot project done in conjunction with Iowa DOT, Buchanan County, FHWA, local contractors and Lafarge will be monitored for long term durability.


Cudrex Viaduct, Switzerland, 2016

UHPC overlay prior to installation of asphalt layer

Work performed at night on weekends with traffic back on Mondays

30 mm (1.25 in) waterproofing overlay 45 mm (1.75 in) used on curbs and sidewalk for deicing protection

Built in 1968440 m (1,450 ft) long9.5 m (31 ft) wide deck24,000 cars/trucks per day230 m3 (300 yd3) of UHPC

Main issue: Waterproofing at end of its life, supporting structure in good shape

Solution: Thin structural UHPC overlay provides waterproofing. Option with minimal traffic interruption.

UHPC cost comparable but more durable than other options.

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443 m (1,450 ft) x 9.5 m (31 ft) wide deck

Cudrex Viaduct, Switzerland, 2016


Kanderal Bridge, Switzerland, 2017


Kanderal Bridge, Switzerland, 2017


Mission Bridge, Abbotsford, BC, 2014

Completed project

Pier prior to final retrofit

230 mm (9 in) thick UHPC jacket used on a height of 3.5 m (11.5 ft) along with additional dowels and a rebar cage to confine the area.

Main issue: Final stage to complete the retrofit of the bridge. One pier on the south shore required additional work because of pour soil conditions.

Solution: Using a UHPC jacket allowed for a thin layer that does not obstruct the view or significantly alter the original appearance.

UHPC cheaper than using soil consolidation techniques.

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Completed project

Delivery to the site (total of 4 trips)

Hoisting and casting from the top of the formwork

Loading and batching in ready‐mix truck at Lafarge plant

Mission Bridge, Abbotsford, BC, 2014


CN Rail Bridge, Montreal, Quebec, 2013

Damaged pier prior to repair

UHPC jacket ‐ Ramp to Pont Victoria under the CN Rail track

115 mm (4.5 in) thick UHPC jacket cast around an existing pier which is 600 mm (2 ft) thick x 3.5 m (11.5 ft) in height.

Main issue: Deteriorated surface due to rebar corrosion and chloride spray because of the very narrow lanes.

Solution: Owner wanted to minimize maintenance and required a material with very low porosity and that could last at least twice as long compared to normal concrete.


Casting – traffic maintained on adjacent lane

Completed repair

Formwork

CN Rail Bridge, Montreal, Quebec


Grafstal Bridge, Switzerland, 2016

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Grafstal Bridge, Switzerland, 2016


Hooper Road Bridge, Union, NY, 2014

Completed connections

New precast pier cap set on existing columns

UHPC used to connect new precast pier cap elements to existing columns. Part of a 21‐day structure replacement.

Main issue: Original detail called for ducts and drilling of a total of 84 holes in the existing columns and grouting of each individual holes. Difficult to implement on site and potential for many delays and issues.

Solution: UHPC connection; initiated by the Contractor who was looking for an alternative solution. Saved 2 days on the schedule. Very short development length of 280 mm (11 in) required for the joint because using UHPC.




(280 mm)

(1,020 mm)

(325 mm)

(1,070 mm ) 3’‐6” column diameter

existing and new #9 bars(28.6 mm) 1.1” in diameter

Female coupler cast in

Male coupler shipped looseExisting rebar

to remain

UHPC


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Precast UHPC slab ready to be anchored

Details of the bridge widening

Precast 200 mm (8 in) thick UHPC slabs added to extend the bridge by 1.5 m (5 ft).

cantilevered slabs are anchored to the existing structure with mechanical anchors.

Main issue: Narrow structure needed to be retrofitted to accommodate larger vehicles and provide a proper protected sidewalk

Solution: taking advantage of the flexural capacity and durability. Underside is exposed to elements. Low cost option in this case.

Pont de la Tine, Switzerland, 2011


Francis Lewis Blvd., Queens, NY, 2015Removed existing steel angles and associated deteriorated concrete. Add new rebar and use 125 mm (5 in) x 300 mm (12 in) wide UHPC headersMain issue: Steel angle and rebar corrosion damage concrete, affect supporting beams and require maintenance.

Solution: Remove the original problem in header joint, the steel angle and rebar that can corrode. By using UHPC, the corners/edges of the slabs will no longer be affected by chlorides and water penetration.


Link Slabs, Binghamton NY, 2014

Completed slab

Casting

Eliminating joints on bridge decks extends the life of the structure

Main issue: Expansion joints deteriorate over time and water/chloride penetrate and damage the slabs edges and the supporting girders.

Solution: By providing a continuous link on top of the piers (approx. 100 mm thick), water/chlorides can not longer deteriorate the structure. The UHPC slab can flex and the strain‐hardening provided by the steel fibers limit the width of micro cracks while maintaining the integrity of the link slab.

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Link Slabs details, NY, 2016


Contact

Gaston Doiron, P. Eng., M.Eng.Project Manager, Ductal®[email protected]: 416‐579‐7864

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